1. Field of the Invention
The present invention relates to a polyphenylene ether resin composition which provides molded products superior in impact resistance, heat resistance, mechanical strength, and surface appearance and is superior in moldability and flow properties.
2. Description of the Prior Art
Applications of polyphenylene ether resins as engineering plastics are expanding since these resins provide molded products superior in heat resistance, stiffness, etc. However, the applications are restricted in that the molded products are somewhat inferior in surface appearance and impact resistance.
Methods for improving the impact resistance of molded products of polyphenylene ether resins are disclosed in Japanese Patent Publication No. 32731/72, Japanese Patent Application Laid-Open No. 2345/71, etc. These methods comprise blending polybutadiene elastomers with polyphenylene ether resins. According to these methods, however, none of practically useful blends superior in heat stability can be obtained, because unsaturated bonds remain in the blended polybutadiene elastomer and this makes the blend thermally instable.
On the other hand, methods for improving the moldability or processability of polyphenylene ether resins and the impact resistance of molded products of polyphenylene ether resins are disclosed in U.S. Pat. No. 3,361,851, Japanese Patent Publication No. 7069/67, etc. These methods comprise blending polyolefins such as ethylene-propylene copolymers with polyphenylene ether resins. According to these methods, however, the low compatibility of polyphenylene ether resins with the polyolefin may cause delamination in molded products of the blend, when it contains 10% by weight or more of the polyolefin. The surface appearance of such molded products is inferior and the improvement of impact resistance is not much remarkable.
Such being the case, Japanese Patent Application Laid-Open No. 75444/80 and U.S. Pat. No. 4,226,761 disclose methods for improving the impact resistance of polyphyenylene ether resins which comprise blending them with polyorganosiloxane-modified alkenyl aromatic resins and Japanese Patent Publication No. 6379/74 discloses a method for improving the strength of molded products of polyphenylene ether resins which comprises blending them with a polyalkyl(meth)acrylate. However, none of these methods can provide molded products satisfactory in appearance and impact resistance.